Monitoring of engraftment and progression of acute lymphoblastic leukemia in individual NOD/SCID mice

Objective. The aim of this study was to develop an animal model for human acute lymphoblastic leukemia (ALL) in which the kinetics and characteristics of leukemia can be sequentially monitored in individual mice. Materials and Methods. NOD/SCID mice were inoculated intravenously with primary ALL. Progression of leukemia was monitored throughout the development of disease by determination of absolute leukemic cell counts (LCC) in peripheral blood. Results. LCC as low as 104 leukemic cells/mL blood could be detected. ALL cells from 5 of 5 patients engrafted, and after identification of the first leukemic cells in peripheral blood, LCC increased exponentially. Leukemic cells showed specificity of homing to spleen and bone marrow, and LCC strongly correlated with the level of leukemic engraftment in these organs throughout disease progression, demonstrating that LCC are representative for overall leukemic burden. Cytogenetic analysis of leukemic cells recovered after six successive in vivo transfers revealed no major karyotypic changes as compared to primary cells, and selection of the dominant clones was observed. This selection process was reflected by an increase in the rate of leukemic progression as compared to the first inoculation, demonstrating the accuracy with which kinetics of leukemic progression can be studied by determination of LCC. Conclusions. This model is suitable for detailed studies of kinetics and characteristics of ALL in vivo, and it may be useful for monitoring effects of novel therapeutic regimens

Ring chromosome 4 as the sole cytogenetic anomaly in a chondroblastoma: A case report and review of the literature

Chromosome analysis of a chondroblastoma of the right distal femur in a 31-year-old male patient revealed o ring chromosome 4 in approximately one- third of the analyzed cells. The remaining cells had a normal karyotype. These findings were subsequently confirmed by fluorescence in situ hybridization (FISH) with a chromosome-4-specific library. FISH with cosmids pC847.351 (4p16.3) and cT171 (4q35) revealed that fewer than 300 kilobase pairs (kbp) are deleted. To our knowledge, ring chromosome 4 has never been reported in this type of neoplasm. There are, however, several reports of chondroblastoma with other chromosome abnormalities, but the relation of these anomalies to this tumor specifically is unclear. In this report, we also provide a review of the literature concerning cytogenetic studies in chondroblastoma. The possible significance of ring chromosome 4 in this type of tumor is discussed